1. Technical Field
This invention relates generally to vehicle seats and more particularly to a vehicle seat having a motor driven and adjustable headrest portion which includes a seat belt guide for allowing the portion of the shoulder belt which fits over a shoulder of the seat occupant to be vertically adjusted concurrently with the headrest.
2. Discussion
The front seats of passenger vehicles, at present, are required to include some form of shoulder belt assembly which fits across the chest portion of an occupant of the seat for helping to restrain the occupant in the event of an accident. Such shoulder belt assemblies are typically secured, in four door vehicles, to the "B"-pillar of the vehicle's body. The B-pillars extend vertically between the front and rear doors on each of the passenger and driver sides of the vehicle. On two door passenger vehicles the shoulder belt guide is positioned on the portion of the vehicle body immediately behind the front doors of the vehicle. Accordingly, the shoulder belt guide is typically not adjustable vertically in accordance with the height of the seat occupant.
When drivers or passengers of significantly varying heights occupy the vehicle seat, the non-adjustably secured seat belt guide can often provide for an uncomfortable fit of the shoulder belt around the shoulder or neck portion of the occupant. For example, if the occupant is very short the shoulder belt may tend to not wrap comfortably over the shoulder portion of the person but, instead, may be positioned uncomfortably close to the neck or head of the occupant. Conversely, if a tall individual occupies the vehicle seat, the non-adjustably mounted seat belt guide may cause the shoulder belt to be positioned uncomfortably low on the shoulder, thus causing the shoulder belt to dig into the shoulder portion of the occupant. Therefore, adjustable positioning of the shoulder belt guide is highly desirable for providing a comfortable fit when used with persons of varying heights.
Prior attempts at providing some degree of limited adjustability to the shoulder belt have typically involved providing a position adjustable belt guide on the B-pillar which can be moved up and down along the B-pillar. Such systems, however, are not particularly convenient to use and are not useable in two-door vehicles which do not have B-pillars.
Accordingly, it is a principal object of the present invention to provide a vehicle seat having means for allowing an occupant to adjustably position a shoulder belt guide assembly to allow a shoulder belt operating in connection with the shoulder belt guide assembly to be comfortably, adjustably positioned about the shoulder portion of the seat occupant.
It is a further object of the present invention to provide a vehicle seat having an operator adjustable headrest which includes a shoulder belt guide assembly, where the headrest and shoulder belt guide assembly may be adjusted in height by the operator simultaneously via a single switch or other like means.
It is still another object of the present invention to provide a vehicle seat having a seat back portion and independent headrest which is coupled to a mechanism disposed substantially within the seat back portion for adjustably positioning the headrest and shoulder belt guide, simultaneously, relative to the seat back portion.
It is yet another object of the present invention to provide a reinforced vehicle seat which has mounted directly to the seat frame the seat belt assembly and wherein the mechanism for vertically adjusting the position of the headrest and shoulder belt guide is designed to satisfy the structural requirements necessary to withstand the severe belt loads encountered in an accident.